Air filter



Aug. 31 1926.

E. MATHIS AIR FILTER Filed July 27 1925 2 Sheets-Sheet 1 Aug. 31, 1926.

- E. MATHIS AIR FILTER Filed July 27 1925 2 Shee ts-Sheet 2 PatentedAug. 31, 1926.

UNITED STATES EUGENE THIS, OF CHICAGO, ILLINOIS.

AIR FILTER.

Application filed July 27, 1925. Serial No. 46,483.

This invention relates to that class of air filters in which the air tobe cleaned is passed through a porous grid, formed by, a shell orcontainer having reticulated front and rear walls and filled with afibrous mass, usually metal wool or like mineral fibre, which in turncarriesa coating of dust intercepting viscous material, and the presentimprovement has for its various objects:

To provide a structural formation and association of parts in a filtergrid or member, providing a cellular division thereof, with the cellforming walls havingla formation adapted to hold the filtering ling ofloose fibrous material in proper condition, with an avoidance ofunfilled passages at the corners or other edge portions of said fillingsthrough which air could pass in an unfiltered condition.

To provide means for effectually anchoring the inner parts of thereticulated gratings which form the front and rear Walls of the filterrid or member to the cell forming walls 0? the same to prevent buckling,etc., of said gratings during the actual operation of the filter.

To provide a structural arrangement of parts by which the front and reargratings, cell forming walls, etc., are substantially attached to theborder member of the filter grid or unit, and in proper relation one tothe other.

To provide an interengaging structural formation and combination of aremovable filter unit and its stationary. holding frame, providing aclose fit between the adjoining surfaces of the parts to prevent passageof unfiltered air at such points.

To provide a simple and effective means for securing the grid member andits fixed holding frame in substantial and close rela-- tion, and at thesame time providing ready means for the detachment and removal of thegrid member for cleaning, replacement, etc. All as will hereinafter.more fully appear.

In the accompanying drawings:

Fig. 1 is a perspective View of a filter unit and its holding frame,embodying the present invention, with parts broken away and in sectionto illustrate the detail construction of the parts.

Fig. 2 is a detail horizontal section of a side portion of the filterunit and its holding frame in assembled relation.

Fig. 3 is a detail p tersecting portions 0 the cell forming walls of thefilter unit, said portions being shown in separated relation.

Fig. 4 is a detail sectional perspective view of a portion of the filterunit, with one of its fastening appliances mounted thereon.

Fig. 5 is a similar view of a complementary or alignedportion of thefixed unit holding frame.

Fig. 6 is a detail horizontal section of the parts shown in Figs. 4 and5.-

Fig. 7 is a detail sectional elevation on line 7-7, of Fig. 6.

Fig. 8 is a detail end elevation with parts in section 8-8, Fig. 6. i

Like reference numerals indicate like parts in the several views.

The air filtering grid or unit in the present invention is preferably ofthe usual fiat rectangular cell form, comprising a marginal of borderportion 1 of imperforate plate metal, and front and rear walls 2 and 3of reticulated material, and usually of a composite type with each wallcomprising an inner sheet or layer of fine woven wire and an outerprotecting sheet of coarse reticulated metal usually the expanded sheetmetal of commerce.

In the present improvement, the marginal or border portion 1 is formedat its rear end erspective view of in-- with an inturned flange 4,adapted to provide a marginal support for the reticulated rear wall 3aforesaid, while at its front end the border portion 1 is formed with anout turned flange 5, which provides a marginal support for thereticulated front wall 2 aforesaid, with said flange 5 having a rebentflange or web 6, which is folded upon the wall 2 to secure the same inplace in a substantial manner.

In connection with the above described parts, intersecting vertical andhorizontal partition plates or walls 7 and 8 are arranged in the cavityof the unit to divide the same into a plurality of cells or subchambersfor the reception of loose masses 9 of fibrous or like air filteringmaterial, to more effectively provide against the usual settling ormatting down action to which larger masses of such material would beliable. The described cellular formation, in a broa sense, is old in thepresent and allied arts, t e feature of novelty in the constructionshown involving the formation of the v lar construction,

partition lates or walls 7, 8, aforesaid, with a series 0 corrugations 7and 8 extending lengthwise of'the respective plates or walls and adaptedto provide a sinuous surface formation into which settles, to retard orprevent air leakagealong such surfaces, which is liable to take placewith the usual plane surface partitions, and especially at the points ofintersection of thepartitions and the corners. of the sub-chambers orcells formed by said partitions.

Another feature of the present improve ment in connection with theaforesaid celluconsists in the provision of a series of tie members orloops 10 in associated relation to the points of intersection of thepartitions 7, 8, with said loops adapted to embrace and tie the frontand rear walls 2, 3, in close relation to said partitions with a view toprevent movement of the central portions of said walls away from saidpartitions.

In the practical application of the filter grid or unit, the same isremovably supported in a holding frame fixedly secured to and forming apart of an induction duct of the ventilating apparatus of school andlike buildings. In its preferred form, said holding frame is ofrectangular shape, complementary to the filter grid or unit, andcomprising main plates or webs 11 of platezmetal, with such webs formedwith inturned flanges 12 and 13 at their respective front and rearsides, and with each rear flange 13 having a greater Width than thefront flange 12, in order that the excess width Will provide an abutmentface for the inner face of, the

filter grid or unit, when the same is in place, as illustrated in Figs.1, 2 and 6.

Another part of this improvement involves in connection with a holdingframe and filter grid or unit of substantially the same construction asabove described, of a fastening means for detachably securing thefilter, grid in said holding frame, the

same comprising a detail construction as follower A cylindrical stem 14carrying an operating head 15 at one end and a transverse latching pin16 at its other end is ,re'volubly mounted in an orifice formed thereforin the out turned marginal portion or flange 5 of the filter grid, andin a manner permitting longitudinal turning movement 0 said stem by theoperator.

Associated with the middle portion of the stem 14 is a coiled spring 17,of which is to force the headed end of said stem away from the flange ofthe filter unit in which the stem is mounted as above set forth. Inconnection with the described construction the front flange 12 of theunit holding frame is formed with an elongated orifice 18 for thepassage of the transverse latching pin 16 of the stem 14, so that within Figs. 6, 7,

the tendency the filter unit in place in its holding frame, theworkmancan press the stem 14 inwardly against the stress of the spring17 and cause the latching pin 16 to pass entirely through the elongatedorifice 18 of the holding frame. ith the parts in such relation aturning movement of the stem 14, the transverse latching pin 16 is movedcrosswise of the elongated orifice 18, as shown and 8, to lockthe partstogether, with the spring 17 acting to hold the same tightly and firmlyin close contact.

.The filter grid or unit 'willbe provided with the usual handles 19 forconvenience in handling in an assembly, removal or repair of the filterunit parts.

The referred material used as the fibrous fi sists of a knitted fabric,preferably tubular, of thin flat filaments or threads of metalliccopper, with such knitted fabric crumpled upon itself to form afiltering mass of the required size and shape, and with the filaments orthreads of the mass coated with an oleaginous or other suitable viscousfluid to aid 1n the interception and retention of dust and otherimpurities from the body of air passing through the filter rid.

Having thus fully descri ed my invention what I claim and desire tosecure by Letters Patent is:-

1. An air filter unit of the type described, comprising a border memberof imperforate metal, front and rear walls of perforate material,partitions in angular relation in said border member to provide aplurality of sub-chambers, fillings of fibrous material in saidsub-chambers, said partitions being formed with corrugations along theirlen th.

2. An air filter unit of the type descri ed, comprising a border memberof imperforate metal, front and rear walls of perforate material,partitions in angular relation in said border member to provide aplurality of sub-chambers, fillings of fibrous material in saidsub-chambers, and a series of confining loops embracing intersectingportions of said partitions and the front and rear walls of the unit.

3. An air filter unit of the type described,

comprising a border member of imperforate material and having aninturned flange at its rear end and an out turned flange at its frontend, said out turned flange having an extension adapted for rebending, arear wall of reticulated material having bearing onthe rear inturnedflange of the border member, a front wall of reticulated materialresting on the aforesaid out turned flange of the border member and heldin place by the rebent portion of said flan e.

4. An air filter unit of t e type described, comprising a border memberof imperforate material and having an inturned flange at itsling mass 9of the fil'ter unit con- III Ill

rear end and an out turned flange at its front end, said out turnedflange having an extension'adapted for rebending, a rear wall ofreticulated material having bearing on the rear inturned flange of theborder member, a front wall of reticulated material resting on theaforesaid out turned flange of the border member and held in'place bythe rebent portions of said flange, and a series of partitions arrangedin angular relation and dividing the interior of the unit intosubchambers for the reception of fibrous filtering masses.

lateral flanges at its front and rear edges,

the rear flange being of greater extent than the front flange to providea marginal bearing for the inner side of the unit, with the front flangeof the fixed frame and the out turned flange of the filter unithavingassociated relation for the reception of fastening means between theparts.

6. -An air filter unit of the type described, comprising a border memberof imperforate material and having an inturned flange at its rear end,and an out'turned flange at its front end, a rear wall of reticulatedmaterial having bearing on the rear inturned'flange' of the bordermember, a front wall of reticulated material restin on the front outturned flange of the bor er member, a fixed frame for holding the filterunit formed with an imperforate wall having lateral flanges at its frontand rear edges, the rear flange being of greater extent than the frontflange to provide a marginal bearing for the inner side of the unit withthe front flange of the fixed frame and the out turned flange of thefilter unit having associated relation for the reception of fasteningmeans between the parts, said fastening means comprising a headed andspring impelled stem having a v transverse pin at its inner end andrevolubly and slidingly mounted in the out turned flange of the filterunit, the front flange of the holding frame having an elongated slot inaligned relation to said stem for the passage and engagement thereof.

7 An air filter unit of the type described, comprising a border memberof imperforate material having an out turned flange at its front end,front and rear Walls of reticulated material attached to said bordermember, and a fixed frameproviding a support for the filter unit andhaving an imperforate wall and alateral flange providing an abutment forthe filter unit, said lateral flange and the out-turned flange of thefilter unit,

having associated relation for the reception of fastening means betweenthe parts, said fastening means comprising a headed and spring impelledstem havin a transverse pin at its inner end and revo ubly and slidinglymounted in a mar inal flange of the filter unit, the lateral fl framehaving an elongated slot in ali ned relation to said stem for thepassagean enga ement thereof.

igned at Chicago, Illinois, this 23rd day of July, 1925.

EUGENE Marnie.

ange of the fixed

